TiO2 nanoparticles anchored on graphene oxide nanosheets as a highly active photocatalyst for decabromodiphenyl ether degradation

Man Yang,Yilun Zou,Lei Ding,Yang Yu,Jinai Ma,Lei Li,Ande Fudja Rafryanto,Jing Zou,Arramel,Haitao Wang 한국탄소학회 2023 Carbon Letters Vol.33 No.5

Decabromodiphenyl ether (BDE209) is a persistent aromatic compound widely associated with environmental pollutants. Given its persistence and possible bioaccumulation, exploring a feasible technique to eradicate BDE209 efficiently is critical for today’s environmentally sustainable societies. Herein, an advanced nanocomposite is elaborately constructed, in which a large number of titanium dioxide ( TiO2) nanoparticles are anchored uniformly on two-dimensional graphene oxide (GO) nanosheets ( TiO2/GO) via a modified Hummer’s method and subsequent solvothermal treatment to achieve efficient photocatalytic degradation BDE209. The obtained TiO2/ GO photocatalyst has excellent photocatalytic due to the intense coupling between conductive GO nanosheets and TiO2 nanoparticles. Under the optimal photocatalytic degradation test conditions, the degradation efficiency of BDE209 is more than 90%. In addition, this study also provides an efficient route for designing highly active catalytic materials.

Impact of the COVID-19 pandemic on student teachers: how the shift to online collaborative learning affects student teachers’ learning and future teaching in a Chinese context

Man Lei,Jane Medwell 서울대학교 교육연구소 2021 Asia Pacific Education Review Vol.22 No.2

In March 2020, universities in China transitioned to online education in response to the COVID-19 pandemic and intensified the focus on collaboration in online learning. However, little is known about the impact of undertaking online collaborative learning (OCL) on student teachers’ views about the process and about their own teaching and learning. This qualitative study examined 18 student teachers’ views about their experience of OCL and the way it affected them as learners and future teachers. The participants reported that OCL helped them develop varied views of learning and had a positive effect on their views about the future use of OCL. They saw their personal experience of OCL as an important aspect of their development as teachers. These findings highlight ways that online learning can shape the views and professionalism of student teachers. Future teacher training programs can provide OCL as a teaching experience at an early stage to help transform student teachers’ self-understanding from that of a student to that of a teacher. The findings of this study further reveal that online collaborative teacher training offers student teachers an opportunity to collaborate, discuss, and reflect on their professional development as teachers. This encourages teacher educators to reconsider how new forms of practice and teaching theories can be woven together more effectively in post-COVID teacher training.

A Study on the Bending Mechanism of the Flexible Ureteroscope

Man-Cheong Lei,Ruxu Du 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

Flexible ureteroscope is increasingly used for urologic treatment today. The key mechanism of the ureteroscope is the bending mechanism. It consists of a bending head and a control lever connected through a set of wire. The lighting and imaging optics as well as the surgical tools all go through the bending head. With the demand for improved performance and reduced size, more research on its design is still needed. In this paper, the modeling and simulation of an ureteroscope are presented, which pave the road for design optimization in the future.

A Correlation Research of Moral behavior in Physical Education Learning Process of College Students in Shanghai

( Si Man Lei ),( Yan Xiu Cai ),( Mei Jun Teng ),( Chen Song Wang ) 한국체육학회 2015 국제스포츠과학 학술대회 Vol.2015 No.1

Purpose: The study was to explore the relationship between physical education, moral education and moral behaviors, and the difference of moral behaviors among college students in Shanghai. Method: The targeted voluntary participants were 399 college students in Shanghai. Data were collected through administering self-report scale of Moral behavior in Physical Education was used, which with Cronbach`s alpha is .983. It is designed to investigate the relationship between individual`s demographic background (age, gender, grade, self-perceived academic performance, socioeconomic status and self-esteem), participating sports types, and the seven moral behaviors (self-directed learning, motivation of sport participation, individual goal orientation, responsibility, respect, leadership and caring). For group differences, correlation study and regression investigation were interpreted through data analysis in SPSS 20.0. Result: 1) It can be found having no time is the main reason for not participating in extracurricular physical activities. 2) The moral education, physical and mental health, compliance and equality, integrity and diligence and self-improvement and cooperation were correlated significantly. 3) There was gender difference on active participation. 4) Physical and mental health, active participation, self-orientation, leadership were positively correlated with the overall moral behavior scale. Conclusion: College students who participate more in exercise have better performance on moral behavior. Therefore college students should do more exercises. Considering that integrity and diligence, self-improvement and cooperation, and offering help that sport club participants scored higher than non-participants, we should encourage college students to participant in more sport clubs. Changing traditional teaching model, searching for new methods in improving moral education and further promoting the integration of physical and moral education is needed. A relevant curriculum could be established in future teaching program.

Extraordinary Optical Transmission and Enhanced Magneto-optical Faraday Effect in the Cascaded Double-fishnet Structure with Periodic Rectangular Apertures

Chengxin Lei,Zhongsheng Man,Shaolong Tang 한국광학회 2020 Current Optics and Photonics Vol.4 No.2

A significant enhancement of the magneto-optical Faraday rotation and extraordinary optical transmission (EOT) in the cascaded double-fishnet (CDF) structure with periodic rectangular apertures is theoretically predicted by using the extended finite difference time domain (FDTD) method. The results demonstrate that the transmittance spectrum of the CDF structure has two EOT resonant peaks in a broad spectrum spanning visible to near-infrared wavebands, one of them coinciding with the enhanced Faraday rotation and large figure of merit (FOM) at the same wavelength. It is most important that the resonant position and intensity of the transmittance, Faraday rotation and FOM can be simply tailored by adjusting the incident wavelength, the thickness of the magnetic layer, and the offset between two metallic rectangular apertures, etc. Furthermore, the intrinsic physical mechanism of the resonance characteristics of the transmittance and Faraday rotation is thoroughly studied by investigating the electromagnetic field distributions at the location of resonance. It is shown that the transmittance resonance is mainly determined by different hybrid modes of surface plasmons (SPs) and plasmonic electromagnetically induced transparency (EIT) behavior, and the enhancement of Faraday rotation is mostly governed by the plasmonic electromagnetically induced absorption (EIA) behavior and the conversion of the transverse magnetic (TM) mode and transverse electric (TE) mode in the magnetic dielectric layer.

The Heroic Journey in Yeats's Cuchulain Plays

Du, Lei,Xiao, Yongmei,Kang, Seung-Man The International Promotion Agency of Culture Tech 2021 International Journal of Advanced Culture Technolo Vol.9 No.3

According to Joseph Campbell, there is always a similar pattern in the hero myth, which is called hero's journey. The legends about Cuchulain, the great Irish warrior, also follow this pattern. W. B. Yeats adapts the legends into his plays with Cuchulain as the protagonist. This paper discusses the protagonist's heroic journey in the five Cuchulain plays written by Yeats. In the five plays, Cuchulain grows, matures, weakens, dies, and resurrects, completing and meanwhile sublimating his heroic journey. In At the Hawk's Well, Cuchulain shows potential qualities of a hero. The Green Helmet displays his self-growth through the depiction of his heroic merits which make him a true hero. In On Baile's Strand, the hero suffers from the major frustrations and tribulations in his heroic journey and is stricken down consequently. The Only Jealousy of Emer reflects the hero's inner struggle and vulnerability. The last play, The Death of Cuchulainn, marks the end and reincarnation of the hero's life. Through the depiction of Cuchulain's heroic journey in the five plays, his heroic qualities are well demonstrated. Meanwhile, Yeats's views of heroism can be found as well.

Dietary methionine supplementation to a low-protein diet improved hair follicle development of Angora rabbits

Zhao Man,Wang Tongtong,Wang Bin,Liu Chuanhua,Li Fuchang,Liu Lei 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.6

Objective: Angora rabbits fed a low-protein diet exhibit decreased hair production performance. This study was set out to evaluate the effects of methionine on hair properties and nitrogen metabolism in Angora rabbits fed a low-protein diet and to investigate the gene expression related to hair follicle development to determine the possible molecular mechanism of methionine effects on hair follicle development. Methods: An experiment was conducted to investigate the effects of DL-methionine addition on a low-protein diet on hair development in Angora rabbits. Angora rabbits were divided into 5 groups: fed a normal diet (control), fed a low-protein diet (LP), or fed an LP supplemented with 0.2%, 0.4%, or 0.6% DL-methionine (Met). Results: The results showed that rabbits in the LP group had lower wool yield than the control rabbits, but the addition of 0.4% to 0.6% Met to LP attenuated these effects (p< 0.05). Dietary addition of 0.4% to 0.6% Met to LP increased the apparent nitrogen digestibility, nitrogen utilization rate, and feed efficiency (p<0.05). Feeding LP decreased the insulinlike growth factor 1 (IGF1), keratin-associated protein (KAP) 3.1, and KAP 6.1 mRNA levels compared with the control, but the addition of 0.4% Met in LP attenuated these effects (p<0.05). Relative to the LP or control group, dietary addition of 0.4% Met increased versican mRNA levels. Conclusion: In conclusion, the addition of Met to LP could improves wool production performance and feed efficiency and reduce nitrogen emissions in Angora rabbits. Met can promote hair follicle development, which may be associated with IGF1, KAP, and the versican signaling.

〈학술논문〉하이포 트로코이드 기어펌프의 접촉응력과 건마멸 특성에 관한 연구

권순만(Soon-Man Kwon),심무용(Muyong Sim),여뢰(Lei Lu),신중호(Joong-Ho Shin) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

The contact stress in a hypotrochoidal pump is addressed in this paper because it cannot be adjusted for wear. The first part of this paper presents a simple and exact rotor profile equations of the hypotrochoidal pump. In the second part of this paper, an explicit formular to avoid undercut in the outer-rotor of the hypotrochoidal pump is proposed by examining the minimum radius of curvature of the inner-rotor tooth profile on the convex section. Next, the contact stresses without hydrodynamic effect between the inner and outer-rotors are evaluated through the calculation of the Hertzian contact stress between the rotors' teeth. Based on the above results, we finally present the wear characteristics of p<SUB>H</SUB>V<SUB>s</SUB>. factor, which is proportional to the wear rate, between the rotors of the hypotrochoidal pump under quasi-static and dry contact conditions.

Two Low-Loss Large Current Rectifiers Based on Low KVA Rating Wye-Connected Autotransformers

Meng, Fangang,Man, Zhongcheng,Li, Quanhui,Gao, Lei The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.6

In this paper, two large current rectifiers are proposed based on two wye-connected autotransformers. The requirements of the ideal large current rectifier are analyzed, and it is concluded that the large current rectifier has a higher power density and a higher energy conversion efficiency when it is made up of two three-phase half-wave rectifiers and a wye-connected autotransformer. According to theoretical analysis results, the two novel wye-connected autotransformers are designed to feed two three-phase half-wave rectifiers. The two autotransformers can generate two groups of three-phase voltages with a 60o phase shifting, and their kVA ratings account for 95% and 80% of the load power, respectively. These values are less than those of a double star rectifier at 30% and 46%. From the input mains and output side, the power quality of the proposed rectifiers is the same as that of the double star rectifier. Some experiments validate the correctness of the theoretical analysis.

제로터 펌프의 마멸 최적설계에 관한 연구

권순만(Soon-Man Kwon),남형철(Hyoungchul Nam),여뢰(Lei Lu),신종호(Joong-Ho Shin) 대한기계학회 2009 大韓機械學會論文集A Vol.33 No.1

A disadvantage in the design of gerotor pump is a lack of parts that can be adjusted to compensate for wear in the rotor set, and as a consequence, it causes a sharp reduction of efficiency. In this paper, an attempt has been made to reduce the wear rate between the rotors of a gerotor pump. To do this, floating genetic algorithm (FGA) is used as an optimization technique for minimizing the wear rate proportional factor (WRPF). The result shows that the wear rate can be reduced considerably, e.g. approximately 8% in this paper, throughout the optimization using FGA.